A known example of a DAC requiring these settings is the Analog Devices AD1955. This type of DAC requires the following jumper settings:

The input connections should follow the Scheme shown underneath:

All Ground connections must be made to the DAC’s Analogue Ground Pin. All Vcom connections from the Universal Tube Output Stage must be made to the “Reference Voltage (Vref)” or “Common Mode Voltage (Vcom)” Pin(s) on the DAC. An additional 51 Ohm Resistor needs to wired in each channel between “In” and “Vcom”.